TOPIC: 1991 Chevy G20 Van 4.3L v6 UK import

Ok so one of my friends at works got a G20 import. He says he does quite a lot of long runs in this van. Has anyone got any experience with this type of vehicle and any results to share?

Hi Phil,

The year may be helpful, auto manufacturers do have a tendancy to make production changes...

There are a few posts on Chevrolet 4.3L V6 engines.

If it is the fly-by-wire throttlebody with the contoured venturi, you'll need a scanner to determine the throttleplate position. Also, with this type, keep in mind the off position is not the closed position.

You want to reroute the PCV hose to the air intake plenum (and cap the manifold port), close to the TB. expect a little oily residue, that is what accumulates when you draw gases containing oil vapor through a hose.

Check your vacuum lines for leaks.

If this one is similiar to other models it may not be the easiest engine to access.

Karl Fortner
Tacoma, Washington

Yes its a 1991. Its had the cat taken off as the legislation in the UK didnt require a cat on that age vehicle.

I knew there was at least one person that was going to do one of these
Welcome to Gadgetman Land! The Gadgetman Groove: The World's Best in Fuel Economy

Markus was going to do a 1989.

You can add a comment to the post linked above which will generate an e-mail to him.

Other than that, It has a TB and runs on gas... have at it.


Karl Fortner
Tacoma, Washington.

The 91 is MAYBE a TBI system. If so, you are in GREAT luck. He will be amazed.

On the computer controlled throttles, it is NOT necessary to have a scanner. If you simply look at the throttle body, you can tell by the staining where the natural idle location is.

Simply wedge the plate into that position, leaving a little (maybe 1mm) of the black visible on the upstream side of the plate. Then, cut The Groove as normal.

Some have very rounded outputs. In this case, you increase the angle of the bit to accommodate for it. It will feel weird being so steep, but it's the angle of The Groove relative to the wall.

Remember that and you'll do fine.

It is a TBI system,I know that much

You will want to view and subscribe with email updates to GroovyServiBulletins on YouTube. EVERYBODY should!

Here's a video pertinent to your application:

This owner is REALLY going to be thrilled!